The Research And Implement Of Real-time Transmission System On IP Video Telephone

With the development of Internet technology, the transmission of data on the network is no longer confined to text and images, to the information needs of people also gradually shift to voice and video, multimedia format, which make IP video phone rapidly develop, it is Using IP network for real-time voice, video transmission, and effectively make use of the existing network bandwidth. With all aspects of society the rapidly developing, The IP video phone will become an important component in the life , it applies not only to family life, but also can be widely used in various business activities, distance learning, security monitoring, medical diagnosis, scientific investigation etc,for a variety of different fields.This paper mainly make a rearch on the principle of IP video phone, and make a brief study on key technology of video phone , on the basis of existing hardware platforms, develop a real-time transmission of video phone system. Through the study of the principle of IP video telephony, we understand video telephony IP the workflow. The IP telephony use the Real-time Transport Protocol - RTP / RTCP, through the research, we in-depth understanding of the network transmission to the basic technology, the RTP protocol is on the basis of the UDP, UDP does not provide any response mechanisms in it's layer, and do not provide any flow control mechanisms. Although it is not reliable, but can be better guaranteed real-time, follow-up data will not lose time effectiveness.In addition, the paper also analysis g.729a audio coding and video coding h.264 ,they were using high compression rate coding method to processing the original data, can make better use of existing bandwidth. Hardware platform is based on s3c2440A, which includes A / D,D / A converter AD1885, JTAG interface, USB, networks, RS323 serial ports, power and reset, Mike, headsets, cameras first class, to meet the hardware IP video phone need to the software, soft platform is the embedded linux operating system, through the application of procedures to achieve the IP video phone on the use of audio and video data transmission on RTP protecol.In this paper, the realization of IP video phone transmission system, mainly solve the transmission of multimedia data in the course of a number of issues, in the use of high compression rate speech codec compression method and the high rate of video codec to process the raw data, greatly improving the hardware platform the pace. Have the necessary broadband small, the utilization rate of resources, the advantages of low cost, resulting in a wide range of applications.